title: Mouse basophils reside in extracellular matrix-enriched bone marrow niches which control their motility.
abstract: Basophils co-express FcεRIα and CD49b, the α-2 chain of integrin-type receptor VLA-2 (α2β1), which recognizes type-1 collagen as a major natural ligand. The physiological relevance of this integrin for interactions with extracellular bone marrow matrix remains unknown. Herein, we examined the expression of several receptors of this family by bone marrow-derived basophils sorted either ex-vivo or after culture with IL-3. Having established that both populations display CD49d, CD49e and CD49f (α-4, α-5 and α-6 integrins subunits, respectively), we addressed receptor functions by measuring migration, adhesion, proliferation and survival after interacting with matched natural ligands. Type I collagen, laminin and fibronectin promoted basophil migration/adhesion, the former being the most effective. None of these ligands affected basophil viability and expansion. Interactions between basophils and extracellular matrix are likely to play a role in situ, as supported by confocal 3D cell imaging of femoral bone marrow sections, which revealed basophils exclusively in type-1 collagen-enriched niches that contained likewise laminin and fibronectin. This is the first evidence for a structure/function relationship between basophils and extracellular matrix proteins inside the mouse bone marrow.
authors.affiliation: Laboratory of Cell Biology, Institute of Biological and Health Sciences, Federal University of Alagoas, Maceió, Brazil.
authors.forename: Salete
authors.initials: S
authors.lastname: Smaniotto
authors.forename: Elke
authors.initials: E
authors.lastname: Schneider
authors.forename: Nicolas
authors.initials: N
authors.lastname: Goudin
authors.forename: Rachel
authors.initials: R
authors.lastname: Bricard-Rignault
authors.forename: François
authors.initials: F
authors.lastname: Machavoine
authors.forename: Mireille
authors.initials: M
authors.lastname: Dardenne
authors.forename: Michel
authors.initials: M
authors.lastname: Dy
authors.forename: Wilson
authors.initials: W
authors.lastname: Savino
mesh_terms: D000818:Animals; D001491:Basophils / Q000166:cytology* / Q000378:metabolism; D001854:Bone Marrow Cells / Q000166:cytology* / Q000378:metabolism; D002448:Cell Adhesion; D002465:Cell Movement; D002478:Cells, Cultured; D005109:Extracellular Matrix; D005260:Female; D005455:Fluorescent Antibody Technique; D020869:Gene Expression Profiling; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D060888:Real-Time Polymerase Chain Reaction